0.7.13.21:

[sbcl.git] / src / compiler / array-tran.lisp

diff --git a/src/compiler/array-tran.lisp b/src/compiler/array-tran.lisp
index eb3f9df..a384a6c 100644 (file)
--- a/src/compiler/array-tran.lisp
+++ b/src/compiler/array-tran.lisp
@@ -227,7 +227,10 @@
         (destructuring-bind (type-spec &rest rest) args
           (let ((ctype (specifier-type type-spec)))
             (apply #'!make-saetp ctype rest))))
-       `((base-char ,(code-char 0) 8 ,sb!vm:simple-string-widetag
+       `(;; Erm.  Yeah.  There aren't a lot of things that make sense
+        ;; for an initial element for (ARRAY NIL). -- CSR, 2002-03-07
+        (nil '#:mu 0 ,sb!vm:simple-array-nil-widetag)
+        (base-char ,(code-char 0) 8 ,sb!vm:simple-string-widetag
                    ;; (SIMPLE-STRINGs are stored with an extra trailing
                    ;; #\NULL for convenience in calling out to C.)
                    :n-pad-elements 1)
@@ -366,14 +369,17 @@
                                   'length
                                   `(+ length ,n-pad-elements)))
           (n-words-form
-           (if (>= n-bits-per-element sb!vm:n-word-bits)
-               `(* ,padded-length-form
-                   (the fixnum ; i.e., not RATIO
-                     ,(/ n-bits-per-element sb!vm:n-word-bits)))
-               (let ((n-elements-per-word (/ sb!vm:n-word-bits
-                                             n-bits-per-element)))
-                 (declare (type index n-elements-per-word)) ; i.e., not RATIO
-                 `(ceiling ,padded-length-form ,n-elements-per-word)))))
+           (cond
+             ((= n-bits-per-element 0) 0)
+             ((>= n-bits-per-element sb!vm:n-word-bits)
+              `(* ,padded-length-form
+                (the fixnum ; i.e., not RATIO
+                  ,(/ n-bits-per-element sb!vm:n-word-bits))))
+             (t
+              (let ((n-elements-per-word (/ sb!vm:n-word-bits
+                                            n-bits-per-element)))
+                (declare (type index n-elements-per-word)) ; i.e., not RATIO
+                `(ceiling ,padded-length-form ,n-elements-per-word))))))
       (values
        `(truly-the ,result-type-spec
         (allocate-vector ,typecode length ,n-words-form))